The answer is D.
Melatonin is a molecule that is produced in the pineal gland and secreted into the blood. Melatonin then travels to different parts of the brain. It tells the brain and the rest of the body about the time of wake and sleep. It causes drowsiness and decreases body temperature to assist in the regulation of the sleep/wake cycle. The melatonin secretion into the blood is regulated by the endocrine system, by the hypothalamus which on gets stimulated by the light.
Answer:
<u>Soil, air & water</u> are 3 abiotic factors in the environment.
What science book do u have?
Answer:
A closed system is a physical system that does not allow transfer of matter in or out of the system, though, in different contexts, such as physics, chemistry or engineering, the transfer of energy is or is not allowed.
